System for cleaning molding equipment using a laser

ABSTRACT

A system for cleaning molds within presses is disclosed wherein the system utilizes a light source including a laser to clean surfaces within the mold. The light source is aligned with an opening in the mold and light from the laser is directed onto the mold surfaces to vaporize residual material thereon to thereby clean the surfaces. The light source may be formed as a portable unit movable between different presses, or the light source may be in the form of a single laser with a plurality of light paths leading from the laser to individual presses such that light may be selectively conveyed along the light paths to clean the molds within the presses.

BACKGROUND OF THE INVENTION

The present invention relates to a system for cleaning moldingequipment, and more particularly, to a system for increasing theefficiency and reducing the cost of cleaning molding equipment by usinga laser.

In a typical molding operation, a mold having interior surfacesconfigured to correspond to the shape of an article to be molded ismounted in a press and the material to be used to form the article issupplied to the mold and molded to the desired shape. When the articleis removed from the mold, a certain amount of residual material remainson the interior mold surfaces. For example, when a molded rubber articleis formed, residual material in the form of small pieces of rubberand/or release agents remain within the mold and must be removed througha cleaning process.

Various cleaning processes have been used for cleaning molds and mostknown cleaning processes incorporate a media which is introduced intothe interior of the mold to impart a physical force to any residualmaterial on the interior mold surfaces whereby the material isphysically removed from the mold. Early known cleaning processesincorporated glass beads as the cleaning media which would be blown orblasted into the mold to perform a sand blasting type of cleaningoperation. Subsequently, plastic beads were introduced as the cleaningmedia in order to reduce the amount of abrasion and possible damagewhich may occur to the interior of the mold tooling. More recently, CO₂has been used as the cleaning media in order to further reduce theabrasive effects of the cleaning operation on the tooling.

A problem associated with glass and plastic beads is the tendency of thebead media to become lodged or trapped within the mold which will have adeleterious effect on articles subsequently formed within the mold.Further, crevices in the mold can be difficult for the media to reach,particularly if the surface is located within a crevice which cannot bedirectly blasted by the media.

In addition, when CO₂ is used as the blasting media, the CO₂ tends toreduce the temperature of the mold such that the mold must be reheatedbefore it can be put back into use in a molding operation.

It should also be noted that when a cleaning media is used, the moldtooling must typically be removed from the press that it is mounted inand taken to a separate cleaning area for the cleaning operation. Thisremoval of the mold from the press results in a significant down timefor the press both because of the time required to remove and reinstallthe mold and as a result of the mold cooling off during its removal suchthat it must be reheated before the molding operation continues.

Finally, the use of a cleaning media results in increased expense foroperating the molding apparatus in that there is a continuing expensefor the purchase and disposal of the media used for the cleaning.

Accordingly, there is a need for a cleaning system for use with moldswherein down time interfering with the molding operation is minimizedwhile also reducing the operating costs of the cleaning system.

SUMMARY OF THE INVENTION

It is a primary object of the present invention to provide a system andmethod for on-site cleaning of molds mounted in presses, as well asequipment associated with a molding operation, wherein the cleaning isperformed in a non-erosive manner.

In one aspect of the invention a method of cleaning equipment associatedwith a molding operation is provided comprising the steps of: aligning alight source including a laser with the equipment, and activating thelaser to cause light from the light source to impinge on a surface ofthe equipment to thereby clean residual material from the surface.

In a further aspect of the invention, the laser is preferably a pulsedlaser and the light source portable and includes a moveable output endwhich is adapted to be aligned with the equipment. The output end may bedefined as the end of an optical fiber wherein the optical fiber forms aflexible and movable conduit for the light.

The laser may be incorporated into a portable light source which ismovable between different presses for cleaning the molds therein.Alternatively, a central laser may be provided and light conduits, suchas optical fibers, may be provided leading from the laser to individualpresses, and the light conduits may be selectively activated to supplylight to the output ends thereof as required to clean the individualmolds at the different presses.

As light from the laser is directed onto the molding equipment surfaces,residual material on the surfaces thereof is vaporized and therebyremoved from the equipment. In addition, further material is removedfrom the equipment surfaces as a result of it being blown off of thesurfaces as material underneath the blown off material is vaporized.

In a further aspect of the invention, surfaces of the molding equipmentare cleaned by both direct light and by light reflected off of interiorsurfaces of the equipment whereby the various crevices in the equipmentare thoroughly cleaned.

Other objects and advantages of the invention will be apparent from thefollowing description, the accompanying drawings and the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a portable laser unit forpositioning adjacent to different press stations;

FIG. 2 is a partial cross-sectional view showing a mold within a pressand illustrating the path followed from a light pen positioned adjacentto an opening in the mold; and

FIG. 3 is a schematic diagram illustrating the present invention whereina single laser is used to service a plurality of presses in a cleaningoperation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides an efficient and cost effective cleaningsystem incorporating a laser, as well as a convenient system fordirecting light from the laser onto equipment surfaces to be cleanedincluding the use of fiber optics. In addition, it should be noted thatwhile the following detailed description of the invention refers to thecleaning of molds, the present invention is equally suited for thecleaning of equipment associated with a molding operation includingmills, extruders, finishing equipment and mixers.

Referring to FIGS. 1 and 2, the system for the present inventioncomprises a light source 10 including a laser 12 and an optical system18 for directing light from the laser 12 to an opening 14 in a mold 16.The optical system 18 is illustrated in FIG. 2 as a flexible fiber opticlight conduit, but may also be formed by a system of mirrors or otherconventional optical devices for directing laser light to a desiredtarget. The laser 12 is preferably a pulsed laser which delivers highenergy pulses of light, as opposed to a continuous laser which wouldprovide a continuous light beam output, and such a pulsed laser has arelatively low power requirement and may be operated off a conventional110 V power supply.

The mold 16 is typically formed as a metal tooling component which ismounted within a press 20A. As seen in FIG. 1, the light source 10 maybe formed as a portable unit and may be mounted to a cart 22 formovement to a location adjacent to the press 20A, such that the mold 16need not be removed from the press 20A prior to the cleaning operation.FIG. 1 also illustrates a second press 20B which is positioned in alocation in spaced relation to the first press 20A and which alsocontains a mold, and the light source 10 may be moved to a locationadjacent to the second press 20B for servicing the mold therein. Thus,the light source 10 may be moved to a plurality of press stations toclean the molds in each of the stations without requiring the removal ofthe molds to thereby increase the efficiency of the mold cleaningoperation over the prior art cleaning operations.

FIG. 2 illustrates the light source 10 in use during a typical moldcleaning operation. An output end 26 of the fiber optic element 18,which may be in the form of light pen, is aligned with the opening 14 ofthe mold 16 to thereby direct light rays onto surfaces within the mold16. The output end 26 is preferably provided with a configuration whichis easily held by an operator such that the operator may hold the outputend 26 at various incident angles relative to the mold opening 14 tothereby direct the light from the output end 26 onto the differentsurfaces within the mold 16.

As seen in FIG. 2, certain rays impinge directly upon the surfaceswithin the mold, as is illustrated by rays 28 and 30 impinging upon thesurfaces 32 and 34, respectively. Other rays clean the mold surfaces inan indirect manner, as is illustrated by reflected rays 36 and 38impinging upon surfaces 40 and 42, respectively, whereby a thoroughcleaning of the mold 16 is provided. In addition, the light exiting theoutput end 26 may be directed in a diverging pattern such that theintensity of the light at locations which are not immediately adjacentto the output end 26 will be greatly diminished to minimize thepossibility of operator injury if the output end 26 is misdirected.

Residual material left in the mold 16 from a molding operation mayinclude material used to form the molded article, release agents orother residual material. As the light from the output end 26 impinges onthe mold surfaces, the residual material will be vaporized and therebyreleased from the mold surfaces. In addition, less volatile residualmaterial will be blown off the mold surfaces as a result of the morevolatile substances vaporizing underneath the less volatile materials.For example, when a rubber or elastomeric article is molded within themold 16, residual release agent and pieces of rubber will remain in themold and laser light exiting from the output end 26 will cause therelease agent to vaporize and the expansion of the release agent duringvaporization will cause the rubber to blow off of the mold surfaces. Itshould be noted that an air supply (not shown) may be provided at theoutput end 26 to blow air into the mold opening 14 during the cleaningoperation whereby complete purging of the material from the mold isassured.

Referring to FIG. 3, an alternative embodiment of the present inventionis illustrated diagrammatically wherein a single central laser lightsource 110 is provided for servicing a plurality of press stations120A-D. Multiple light paths from the laser light source 110 to theplurality of press stations 120A-D is defined by a plurality of opticalfibers 118 which terminate in individual light pens 126 located at eachstation. The light pens 126 may be actuated by operators at each of thestations 120A-D for a cleaning operation on molds within the stations120A-D. In addition, control of light passing from the light source 110to each of the light paths 118 may be provided through a coupler 144which directs light down the appropriate path 118 as it is needed for acleaning operation, and the coupler 144 may be operated under control ofa central computer (not shown) for monitoring operations at each of thestations 120A-D.

It should also be noted that the light paths 118 may be defined byoptical delivery systems other than the optical fiber system shown suchas by mirrors or other conventional means to direct light to theindividual stations 120A-D.

From the above description, it should be apparent that the present moldcleaning system may be used immediately after an article is formed inand removed from the mold 16, and that the cleaning operation may beperformed without removing the mold 16 from the press 20 such that ahighly efficient cleaning method is provided which substantially avoidsthe cooling of the mold associated with prior art cleaning methods. Inaddition, it should be apparent that the present cleaning method isadapted for cleaning various pieces of equipment associated with amolding operation, and that the present method does not require theintroduction of a cleaning media into the equipment and therefore avoidscontamination of the equipment with a media.

It should also be apparent that by using a laser light source, variousmolding equipment surfaces, including crevices, will be effectivelycleaned by either direct or reflected light such that a more thoroughcleaning of the equipment is assured, and the cleaning is performed in anon-erosive manner to extend the life of the mold tooling and associatedmolding equipment.

While the method herein described, and the form of apparatus forcarrying this method into effect, constitutes a preferred embodiment ofthis invention, it is to be understood that the invention is not limitedto this precise method and form of apparatus, and that changes may bemade in either without departing from the scope of the invention, whichis defined in the appended claims.

What is claimed is: . .1. A method of cleaning equipment associated witha molding operation comprising the steps of: laser..!.. .3. The methodas in claim 1 wherein said light source is portable, and including thestep of moving said light source from alignment with a first surface ofsaid equipment located at a first station into alignment with a secondsurface of said equipment located at a second station..!.. .4. Themethod as in claim 1 wherein said light source comprises a single laserand a plurality light paths for conveying light from said laser to aplurality of distinct molding stations, and including the step ofselectively activating said light paths to selectively clean equipmentassociated with each of said stations..!.. .5. The method as in claim 1wherein said light source includes an optical fiber defining a movableoutput end for alignment with said surface, said optical fiber defininga flexible and movable conduit for said light and said step of aligningsaid light source comprises an operator holding said output end adjacentto said surface..!.. .6. The method as in claim 5 wherein a plurality ofoptical fibers having output ends are provided defining a plurality oflight sources for cleaning equipment at a plurality of separatestations, and including the step of conveying light from a single laserto each of said stations..!.. .7. The method as in claim 6 including thestep of selectively activating one of said optical fibers to cleanequipment at a first station, and subsequently deactivating said oneoptical fiber and activating another optical fiber to clean equipment ata second station..!.. .8. The method as in claim 1 including the step ofcleaning additional equipment surfaces by reflecting said light off ofsaid surface and onto said additional surfaces..!.. .9. The method as inclaim 1 wherein said step of activating said laser causes said residualmaterial to be vaporized..!.. .10. The method as in claim 9 wherein saidstep of activating said laser further causes said residual material tobe blown off of said surface as material underneath the material to beblown off is vaporized..!.. .11. A method of cleaning a surfacecomprising the steps of:providing a light source including an opticalfiber and a laser; aligning an output end of said optical fiber withsaid surface; and activating said laser to cause light to pass throughsaid optical fiber to said output end and impinge on said surface tothereby clean residual material from said surface..!.. .12. The methodas in claim 11 wherein said laser is a pulsed laser..!.. .13. The methodas in claim 11 wherein said optical fiber defines a flexible and movableconduit for said light and said step of aligning said output endcomprises an operator holding said output end adjacent to saidsurface..!.. .14. The method as in claim 11 wherein a plurality ofoptical fibers having output ends are provided defining a plurality oflight sources for cleaning surfaces at a plurality of separate stations,and including the step of conveying light from a single laser to each ofsaid stations..!.. .15. The method as in claim 14 including the step ofselectively activating one of said optical fibers to clean a surface ata first station, and subsequently deactivating said one optical fiberand activating another optical fiber to clean a surface at a secondstation..!.. .16. The method as in claim 11 wherein said cleaning isperformed on a surface located on equipment associated with a moldingoperation..!.. .17. A method of cleaning equipment associated with amolding operation comprising the steps of:providing a light sourceincluding a plurality of optical fibers and a single pulsed laser, eachsaid optical fiber having an output end located at a molding station;aligning an output end of a first optical fiber with a first surface ina first molding station; activating said first optical fiber to therebyclean residual material from said first surface; aligning an output endof a second optical fiber with a second surface in a second moldingstation; deactivating said first optical fiber and activating saidsecond optical fiber to clean said second surface; and wherein saidsteps of aligning said output ends of said first and second opticalfibers comprises an operator holding said output ends adjacent to saidfirst and second surfaces, respectively..!.. .18. A cleaning system foruse in combination with equipment associated with a molding operation,said system comprising: a light source including a laser; means foraligning said light source with said equipment; and wherein activationof said laser with said light source aligned with said equipment causesresidual material attached to surfaces of said equipment to beremoved..!.. .19. The system as in claim 18 wherein said laser is apulsed laser..!.. .20. The system as in claim 18 wherein said means foraligning comprises a light pen having an end adapted to be positionedadjacent to said surfaces of said equipment, said light pen beingconnected to said laser through a fiber optic connection..!.. .21. Thesystem as in claim 18 wherein said light source is formed as a portableunit for movement to locations adjacent to a plurality of molds locatedat different molding stations..!.. .22. A cleaning system comprising: alight source including an optical fiber and a laser; said optical fiberdefining a flexible and movable conduit for conveying light from saidlaser and including an output end for alignment with a surface to becleaned; and wherein activation of said laser with said output endpositioned in alignment with said surface causes residual materialattached to said surface to be removed..!.. .23. The system as in claim22 wherein said laser is a pulsed laser..!.. .24. The systems in claim22 including a plurality of optical fibers having output ends located ata plurality of separate stations wherein light is conveyed from saidlaser through said optical fibers to perform a cleaning operation ateach of said stations..!.. .25. The system as in claim 22 includingmolding equipment, said surface being located on said molding equipmentand said output end being located adjacent to said surface..!.. .26. Acleaning system for use in combination with equipment associated with amolding operation, said system comprising: a light source comprising aplurality of optical fibers and a pulsed laser; said optical fibersdefining flexible and movable conduits for light from said laser, eachsaid optical fiber including an output end located at a respectivemolding station for alignment with a surface on said equipment to becleaned; and wherein activation of said laser with said output endsaligned with said surfaces causes residual material attached to saidsurfaces to be removed..!..Iadd.27. In a process for molding rubberarticles in a mold mounted within a press in which rubber material issupplied to the mold and residual material remains in the mold after therubber article is removed therefrom, an improved method for removingsaid residual material comprising:aligning with an opening in said molda light source, said light source including a laser; and activating saidlaser to cause light rays to impinge on an interior surface locatedinside said mold, said light rays removing said residual material fromsaid interior surface located inside said mold. .Iaddend..Iadd.28. Themethod of claim 27 wherein said mold contains crevices..Iaddend..Iadd.29. The method of claim 27 wherein said light raysvaporize at least a portion of said residual material..Iaddend..Iadd.30. The method of claim 27 wherein said residual materialis in the form of small rubber pieces. .Iaddend..Iadd.31. The method ofclaim 27 wherein said residual material comprises release agents..Iaddend..Iadd.32. The method of claim 27 wherein said mold remains insaid press during removal of residual material therefrom..Iaddend..Iadd.33. The method of claim 27 wherein said residual materialis removed from said mold while avoiding substantial cooling thereof..Iaddend..Iadd.34. The method as in claim 27 including the step ofremoving said residual material by means of light rays reflected offsaid interior surface of said mold and onto additional surfaces of saidmold. .Iaddend..Iadd.35. The method as in claim 27 wherein said lightsource is portable, and including the step of moving said light sourcefrom alignment with said opening in said mold. .Iaddend..Iadd.36. Themethod as in claim 27 wherein said light source comprises a single laserand a plurality of light paths for conveying light rays from said laserto a plurality of said molds, and including the step of selectivelyactivating said light paths to selectively remove said residual materialfrom interior surfaces located inside said molds. .Iaddend..Iadd.37. Themethod as in claim 27 wherein a plurality of optical fibers havingoutput ends are provided defining a plurality of light sources forremoving said residual material from interior surfaces located inside aplurality of said molds, and including the step of conveying light raysfrom a single laser to each of said molds. .Iaddend..Iadd.38. In aprocess for molding rubber articles in a plurality of molds, each saidmold mounted within a press and supplied with rubber material in whichresidual material remains in each said mold after the rubber article isremoved therefrom, an improved method for removing said residualmaterial comprising:providing a light source including a plurality ofoptical fibers and a single laser, each said optical fiber having anoutput end located at one of said molds; aligning an output end of afirst optical fiber with an opening in a first mold; activating saidfirst optical fiber to cause light rays to impinge on an interiorsurface located inside said first mold, thereby cleaning said residualmaterial from said interior surface located inside said first mold;aligning an output end of a second optical fiber with an opening in asecond mold; activating said second optical fiber to cause light rays toimpinge on an interior surface located inside said second mold, saidlight rays removing said residual material from said interior surfacelocated inside said second mold. .Iaddend..Iadd.39. The method of claim38 wherein said light rays vaporize at least a portion of said residualmaterial. .Iaddend..Iadd.40. A cleaning system for use in combinationwith a mold mounted within a press in which rubber material is suppliedto the mold for molding rubber articles and residual material remains inthe mold after the rubber article is removed therefrom, said systemcomprising: a light source including a laser; means for aligning saidlight source with an opening in said mold; and wherein activation ofsaid laser with said light source aligned with said opening in said moldcauses light rays to impinge on an interior surface located inside saidmold, said light rays removing said residual material attached to saidinterior surface located inside said mold. .Iaddend..Iadd.41. The systemas in claim 40 wherein said mold contains crevices. .Iaddend..Iadd.42.The system as in claim 40 wherein said means for aligning comprises alight pen having an end adapted to be positioned with said opening insaid mold, said light pen being connected to said laser through a fiberoptic connection. .Iaddend..Iadd.43. The system as in claim 40 whereinsaid residual material is in the form of small rubber pieces..Iaddend..Iadd.44. The system as in claim 40 wherein said residualmaterial comprises release agents. .Iaddend..Iadd.45. The system as inclaim 40 wherein said light rays vaporize at least a portion of saidresidual material. .Iaddend..Iadd.46. A cleaning system for use incombination with a plurality of molds, each said mold mounted within apress and supplied with rubber material for molding a rubber article inwhich residual material remains in each said mold after said rubberarticle is removed therefrom, said system comprising: a light sourcecomprising a plurality of optical fibers and a laser; said opticalfibers defining flexible and movable conduits for light rays from saidlaser, each said optical fiber including an output end located at arespective one of said molds for alignment with an opening in saidrespective one mold; and wherein activation of said laser with saidoutput ends aligned with said openings in said molds causes light raysto impinge on interior surfaces located inside said molds, said lightrays removing said residual material attached to said interior surfaceslocated inside said molds. .Iaddend..Iadd.47. The system as in claim 46wherein said light rays vaporize at least a portion of said residualmaterial. .Iaddend.